Why did the federal government go to Little Rock, Arkansas?

This question seems to be referring to the crisis that emerged in Little Rock over attempts to integrate Little Rock Central High School in 1957. After a federal district court ruled that Little Rock must integrate its high school, nine African-American students, known henceforth as the "Little Rock Nine," were chosen to do so. As the school year began, angry white mobs formed outside the school to prevent the black students from entering. Arkansas governor Orval Faubus sided with the mobs, even using the state's National Guard to block entry to the school on the grounds that integration would provoke violence and disorder in the city. The issue became problematic for U.S. President Dwight D. Eisenhower for two reasons. First, it was publicized around the world, which was embarrassing for the United States in the midst of the Cold War. It was difficult to claim that the United States represented a beacon of freedom against the Soviet Union with the disturbing scenes playing out in Little Rock in the background. Second, Governor Faubus was directly and flagrantly flouting a federal court order enforcing the Supreme Court's 1954 decision in Brown v. Board of Education. Eisenhower very reluctantly exercised his power to nationalize the Arkansas National Guard and to send in federal troops to forcibly integrate Little Rock Central High School. So it was for these reasons that the federal government came to Little Rock in 1957.